Article Figures & Data
Figures
- FIG 1.
Sample case of ESUS. A–C, Axial diffusion-weighted MR images demonstrate multiple foci of restricted diffusion throughout the left MCA territory, consistent with an embolic stroke. Subsequent work-up for a cardioembolic source was negative. In addition, axial CTA of the cervical carotid artery demonstrates likely atherosclerotic disease resulting in <50% luminal stenosis (D, arrow). Given the diagnostic evaluation with negative findings and a likely embolic source, this patient meets the criteria for ESUS, despite a minimal degree of luminal carotid stenosis.
- FIG 2.
Carotid sonography demonstrating large (≥3 mm), heterogeneous, nonstenotic carotid plaque in a 66-year-old man who presented with acute-onset vision loss in his right eye, suspicious for retinal ischemia. The patient underwent bilateral carotid US. A, B-mode long axis view of the right carotid vasculature demonstrates the presence of a moderately-sized (∼3 mm) complicated plaque in the proximal ICA. A’, Close-up of the plaque demonstrates heterogeneous plaque with areas both hyperechoic (arrow) and echolucent (asterisk). B and B’, Long view of the proximal ICA and carotid bulb (CB) demonstrates heterogeneous plaque as seen in A and A’. C, The left proximal ICA also demonstrates the presence of large (>3mm) heterogenous plaque with hyperechoic (arrow) and echolucent (asterisk) areas. The right-sided plaque may be smaller than the left secondary to recent dislodgment and embolization of plaque material. The patient underwent an appropriate work-up to identify a potential embolic source, which was negative. This patient was diagnosed with ESUS despite the presence of moderately-sized, heterogeneous plaque on the right resulting in <50% luminal stenosis. Although more data are needed relating to plaque US in the context of ESUS, plaque thickness appears to have a consistent association with ipsilateral stroke across the existing literature. To date, plaque echolucency has not been found to have such an association, which is significant. ECA indicates external carotid artery; CCA, common carotid artery.
- FIG 3.
Example of “vulnerable” plaque features as seen on CTA in 3 different patients. A, Ulcerated plaque within the proximal ICA (dashed box) seen on CTA. Inset in A demonstrates an area of slight luminal stenosis with plaque surface irregularity suspicious for ulceration (arrow). B, CTA from a different patient demonstrates hypodense (“soft”) plaque (solid arrow) with a thin band of peripheral calcifications (arrowhead), resulting in luminal narrowing (dashed arrow). Similar findings are seen in C apart from a much thicker peripheral band of calcification. Hypodense plaques may represent the present of LRNC or IPH, though it can be difficult to distinguish between the 2 on CTA. Plaque hypodensity has been reported to be associated with ipsilateral ischemia in patients with ESUS in most studies. Conflicting evidence exists regarding the relationship between surface irregularity, ulceration, and ipsilateral stroke. In contrast, calcification appears to be unrelated to ipsilateral stroke in patients with ESUS.
- FIG 4.
Representative MR imaging plaque features that may have an association with ipsilateral stroke in patients with ESUS. A, MPRAGE of a patient showing an area of hyperintensity within the proximal ICA (left circle), which has a mean intensity value of 200× that of the adjacent sternocleidomastoid muscle (right circle). These findings suggest the presence of IPH. This patient had >50% luminal stenosis. B, T1 Cube (GE Healthcare) imaging of a different patient shows a LRNC. C, MPRAGE in another patient demonstrates multiple features including hypointense areas suggestive of peripheral calcifications (arrowheads), a hyperintense area (dashed arrow) adjacent to the narrowed carotid lumen (curved arrow), and a peripheral area of LRNC (solid arrow). D, The same patient/artery as in C with T1 Cube imaging demonstrating the narrowed lumen (curved arrow) along with peripheral calcifications (arrowheads) and a LRNC (solid arrow). IPH is not as apparent on TI Cube imaging as on MPRAGE sequences. This patient also had >50% luminal stenosis. Strong evidence exists suggesting that IPH is associated with ipsilateral stroke in ESUS. A LRNC as seen on MR imaging has also been consistently reported to have such an association, albeit not to the same degree as IPH.
